Conformational Dynamics of the Single Lipopolysaccharide O‐Antigen in Solution |
| |
| Authors: | Dr. Dmitry Zlenko Dr. Ilya Kovalenko Dr. Marina Strakhovskaya Dr. Alexander Averyanov Prof. Andrey Rubin |
| |
| Affiliation: | 1. Department of Biophysics, Faculty of Biology, M.?V. Lomonosov Moscow State University, Moscow, RussiaThese authors contributed equally;2. Federal Research Clinical Center of Federal Medical & Biological Agency of Russia, Moscow, Russia;3. Department of Biophysics, Faculty of Biology, M.?V. Lomonosov Moscow State University, Moscow, Russia |
| |
| Abstract: | ![]()
The O‐antigen is the most variable and highly immunogenic part of the lipopolysaccharide molecule that covers the surface of Gram‐negative bacteria and makes up the first line of cellular defense. To provide insight into the details of the O‐antigen arrangement on the membrane surface, we simulated its behavior in solution by molecular dynamics. We developed the energetically favorable O‐antigen conformation by analyzing free‐energy distributions for its disaccharide fragments. Starting from this conformation, we simulated the behavior of the O‐antigen chain on long timescales. Depending on the force field and temperature, the single molecule can undergo reversible or irreversible coil‐to‐globule transitions. The mechanism of these transitions is related either to the rotation of the carbohydrate residues around O‐glycosidic bonds or to flips of the pyranose rings. We found that the presence of rhamnose in the O‐antigen chain crucially increases its conformational mobility. |
| |
| Keywords: | antigens cell recognition conformation analysis membranes molecular dynamics |
|
|
